feat: let tables API return a stream (#3170)

src/catalog/src/error.rs

@@ -41,6 +41,14 @@ pub enum Error {
         source: BoxedError,
     },
 
+    #[snafu(display("Failed to list {}.{}'s tables", catalog, schema))]
+    ListTables {
+        location: Location,
+        catalog: String,
+        schema: String,
+        source: BoxedError,
+    },
+
     #[snafu(display("Failed to re-compile script due to internal error"))]
     CompileScriptInternal {
         location: Location,
@@ -270,9 +278,9 @@ impl ErrorExt for Error {
                 StatusCode::InvalidArguments
             }
 
-            Error::ListCatalogs { source, .. } | Error::ListSchemas { source, .. } => {
-                source.status_code()
-            }
+            Error::ListCatalogs { source, .. }
+            | Error::ListSchemas { source, .. }
+            | Error::ListTables { source, .. } => source.status_code(),
 
             Error::OpenSystemCatalog { source, .. }
             | Error::CreateSystemCatalog { source, .. }

src/catalog/src/kvbackend/manager.rs

@@ -35,8 +35,8 @@ use table::table::numbers::{NumbersTable, NUMBERS_TABLE_NAME};
 use table::TableRef;
 
 use crate::error::{
-    self as catalog_err, ListCatalogsSnafu, ListSchemasSnafu, Result as CatalogResult,
-    TableMetadataManagerSnafu,
+    self as catalog_err, ListCatalogsSnafu, ListSchemasSnafu, ListTablesSnafu,
+    Result as CatalogResult, TableMetadataManagerSnafu,
 };
 use crate::information_schema::InformationSchemaProvider;
 use crate::CatalogManager;
@@ -135,18 +135,22 @@ impl CatalogManager for KvBackendCatalogManager {
     }
 
     async fn table_names(&self, catalog: &str, schema: &str) -> CatalogResult<Vec<String>> {
-        let mut tables = self
+        let stream = self
             .table_metadata_manager
             .table_name_manager()
             .tables(catalog, schema)
+            .await;
+        let mut tables = stream
+            .try_collect::<Vec<_>>()
             .await
-            .context(TableMetadataManagerSnafu)?
+            .map_err(BoxedError::new)
+            .context(ListTablesSnafu { catalog, schema })?
             .into_iter()
             .map(|(k, _)| k)
-            .collect::<Vec<String>>();
+            .collect::<Vec<_>>();
         tables.extend_from_slice(&self.system_catalog.table_names(schema));
 
-        Ok(tables)
+        Ok(tables.into_iter().collect())
     }
 
     async fn catalog_exists(&self, catalog: &str) -> CatalogResult<bool> {